1. Duke University; Durham North Carolina
2. University of North Carolina; Chapel Hill
3. Duke University Medical Center and Durham VA Medical Center; Durham North Carolina
4. Northeastern University, and Brigham & Women's Hospital; Harvard Medical School; Boston Massachusetts
5. Comprehensive Physical Therapy Center; Chapel Hill North Carolina
6. Center for Health Services Research in Primary Care; Durham VA Medical Center; Durham North Carolina
7. University of North Carolina; Chapel Hill, and Center for Health Services Research in Primary Care, Durham VA Medical Center; Durham North Carolina